In March 2024, a unique experiment was conducted in northern France as part of the TWAIN project. The goal was to measure the acoustic emissions of an industrial wind turbine from all directions and under various incoming wind conditions.
Twenty-four ground-level microphones were positioned in a circle centered on the turbine. The turbine noise was recorded over four days, in all kinds of atmospheric conditions—from very low wind speeds to very high. After extensive data cleaning and signal processing, our team was able to produce directivity patterns, showing that some directions are noisier than others. Moreover, we also tested wind farm flow control configurations, which are a key focus of the TWAIN project: when a turbine is not aligned with the incoming wind flow, its wake may be deflected away from downstream turbines. This principle can increase the overall electricity production of the wind farm, but what is the impact on noise emissions? Our measurements will help quantify the effect of wind farm control on noise.
This work was first presented at a national congress in Paris, the Congrès Français d’Acoustique in April 2025, and then at two international conferences: the Wind Energy Science Conference in June 2025 in Nantes, and the Wind Turbine Noise Conference in June 2025 in Copenhagen.
